Load supercategory and subcategories from DB, when a category is loaded

src/main/java/de/unipotsdam/cs/toolup/database/DatabaseController.java

@@ -19,7 +19,8 @@ public class DatabaseController {
     public static final String TABLE_NAME_APPLICATION = "application";
     public static final String TABLE_NAME_APPLICATION_FEATURE = "application_has_feature";
     public static final String TABLE_NAME_APPLICATION_CATEGORY = "application_belongs_to_category";
-    private static final String COLUMN_SUFFIX_UUID = "_uuid";
+    private static final String COLUMN_NAME_UUID = "uuid";
+    private static final String COLUMN_SUFFIX_UUID = "_" + COLUMN_NAME_UUID;
     private static DatabaseController instance;
     private SqlStatementFactory sqlStatementFactory;
 
@@ -79,11 +80,11 @@ public class DatabaseController {
 
         ResultSet res = prepQuery.executeQuery();
 
-        return getRelatedIdsFromResultSet(targetBusinessObjectType + COLUMN_SUFFIX_UUID,
+        return getAllIdsFromResultSet(targetBusinessObjectType + COLUMN_SUFFIX_UUID,
                 res);
     }
 
-    private Set<String> getRelatedIdsFromResultSet(
+    private Set<String> getAllIdsFromResultSet(
             String resultColumnName, ResultSet res) throws SQLException {
         Set<String> relatedIds = new HashSet<>();
         while (res.next()) {
@@ -109,6 +110,15 @@ public class DatabaseController {
     }
 
 
+    public Collection<String> loadSubCategories(String uuid) throws SQLException {
+        PreparedStatement prepQuery = sqlStatementFactory.getSelectSubcategories();
+
+        prepQuery.setString(1, uuid);
+        ResultSet res = prepQuery.executeQuery();
+
+        return getAllIdsFromResultSet(COLUMN_NAME_UUID, res);
+    }
+
     public boolean checkIfExistsInDB(BusinessObject aBusinessObject) throws SQLException, InvalidIdException {
         return checkIfExistsInDB(aBusinessObject.getUuid());
     }

src/main/java/de/unipotsdam/cs/toolup/database/SqlStatementFactory.java

@@ -7,6 +7,8 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.Properties;
 
+import static de.unipotsdam.cs.toolup.database.DatabaseController.TABLE_NAME_CATEGORY;
+
 public class SqlStatementFactory {
 
     public static final String SQL_STATEMENTS_FILENAME = "/SQL_Statements.xml";
@@ -67,4 +69,7 @@ public class SqlStatementFactory {
     }
 
 
+    public PreparedStatement getSelectSubcategories() throws SQLException {
+        return getCustomizedStatement("selectSubCategories", TABLE_NAME_CATEGORY);
+    }
 }

src/main/java/de/unipotsdam/cs/toolup/model/BusinessObjectFactory.java

@@ -15,6 +15,7 @@ import static de.unipotsdam.cs.toolup.model.BusinessObject.*;
 public class BusinessObjectFactory {
 
     private static final String KEY_UUID = "uuid";
+    private static final String KEY_SUPERCATEGORY = "supercategory";
     private static final String TABLENAME_FEATURE = "feature";
     private static final String TABLENAME_CATEGORY = "category";
     private static final String TABLENAME_APPLICATION = "application";
@@ -29,22 +30,7 @@ public class BusinessObjectFactory {
         }
     }
 
-    private static BusinessObject createBusinessObjectWithLoadedRelations(String id, String title,
-                                                                          String description) throws SQLException, InvalidIdException {
-        int indexOfFirstSlash = id.indexOf(BusinessObject.ID_DELIMITER_CHAR);
-        String className = id.substring(0, indexOfFirstSlash);
 
-        switch (className.toLowerCase()) {
-            case TABLENAME_APPLICATION:
-                return new Application(id, title, description, db.loadRelatedCategoriesForApp(id), db.loadRelatedFeaturesForApp(id));
-            case TABLENAME_CATEGORY:
-                return new Category(id, title, description, db.loadRelatedApplicationsForCat(id));
-            case TABLENAME_FEATURE:
-                return new Feature(id, title, description, db.loadRelatedApplicationsForFeat(id));
-            default:
-                throw new UnsupportedOperationException("No class defined for this prefix:" + className);
-        }
-    }
 
     /**
      * @param res the result of a database query
@@ -77,17 +63,40 @@ public class BusinessObjectFactory {
     }
 
     private static BusinessObject createBusinessObjectFromResult(ResultSet res) throws SQLException {
-        String id = res.getString(KEY_UUID);
-        String title = res.getString(JSON_KEY_TITLE);
-        String description = res.getString(JSON_KEY_DESCRIPTION);
-
         try {
-            return createBusinessObjectWithLoadedRelations(id, title, description);
-        } catch (Exception e) {
+            return createBusinessObjectWithLoadedRelations(res);
+        } catch (InvalidIdException e) {
             throw new RuntimeException("This should never happen. ID is loaded from DB and cannot be invalid", e);
         }
     }
 
+    private static BusinessObject createBusinessObjectWithLoadedRelations(ResultSet res) throws SQLException, InvalidIdException {
+        BusinessObject loadedBO;
+        String id = res.getString(KEY_UUID);
+        int indexOfFirstSlash = id.indexOf(BusinessObject.ID_DELIMITER_CHAR);
+        String className = id.substring(0, indexOfFirstSlash);
+
+        switch (className.toLowerCase()) {
+            case TABLENAME_APPLICATION:
+                loadedBO = new Application(id, null, null, db.loadRelatedCategoriesForApp(id), db.loadRelatedFeaturesForApp(id));
+                break;
+            case TABLENAME_CATEGORY:
+                loadedBO = new Category(id, null, null, db.loadRelatedApplicationsForCat(id));
+                ((Category) loadedBO).setSuperCategory(res.getString(KEY_SUPERCATEGORY));
+                ((Category) loadedBO).addSubCategories(db.loadSubCategories(id));
+                break;
+            case TABLENAME_FEATURE:
+                loadedBO = new Feature(id, null, null, db.loadRelatedApplicationsForFeat(id));
+                break;
+            default:
+                throw new UnsupportedOperationException("No class defined for this prefix:" + className);
+        }
+
+        loadedBO.setTitle(res.getString(JSON_KEY_TITLE));
+        loadedBO.setDescription(res.getString(JSON_KEY_DESCRIPTION));
+        return loadedBO;
+    }
+
 
     public static BusinessObject createInstance(String id) throws InvalidIdException {
         String type = getTableNameFromId(id);

src/main/resources/SQL_Statements.xml

@@ -3,6 +3,7 @@
 <properties>
     <entry key="selectBO">SELECT * FROM TABLE_NAME WHERE uuid = ?;</entry>
     <entry key="selectAll">SELECT * FROM TABLE_NAME;</entry>
+    <entry key="selectSubCategories">SELECT uuid FROM TABLE_NAME WHERE supercategory = ?;</entry>
     <entry key="insertBO">INSERT INTO TABLE_NAME VALUES (?,?,?);</entry>
     <entry key="insertCategory">INSERT INTO TABLE_NAME VALUES (?,?,?,NULL);</entry>
     <entry key="updateBO">UPDATE TABLE_NAME SET title = ?, description = ? WHERE uuid = ?;</entry>

src/test/java/de/unipotsdam/cs/toolup/database/DatabaseControllerForCategoryTest.java

+package de.unipotsdam.cs.toolup.database;
+
+
+import de.unipotsdam.cs.toolup.model.Category;
+import org.testng.annotations.Test;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import static de.unipotsdam.cs.toolup.model.BusinessObjectTest.*;
+import static de.unipotsdam.cs.toolup.util.AssertionUtil.assertCollectionEquals;
+import static org.testng.Assert.assertEquals;
+
+public class DatabaseControllerForCategoryTest extends AbstractDatabaseTest {
+
+    @Test
+    public void testThatSuperCategoryIsLoadedFromDB() throws Exception {
+        //arrange
+
+        //act
+        Category cat = (Category) db.load(CATEGORY_TEST_ID_11);
+
+        //assert
+        assertEquals(CATEGORY_TEST_ID_13, cat.getSuperCategory());
+    }
+
+    @Test
+    public void testThatSubCategoriesAreLoadedFromDB() throws Exception {
+        //arrange
+        Collection<String> expectedSubCategories = Arrays.asList(CATEGORY_TEST_ID_11, CATEGORY_TEST_ID_12);
+
+        //act
+        Category cat = (Category) db.load(CATEGORY_TEST_ID_13);
+
+        //assert
+        assertCollectionEquals(expectedSubCategories, cat.getSubCategories());
+    }
+}